6 vanilla pods
625ml/1 pint whole milk
50g/2oz skimmed milk powder
120g/4½oz unrefined caster sugar
10 whole coffee beans
6 medium egg yolks
1. Place the vanilla pods on a chopping board and run a small, sharp knife along the length of each pod, cutting it in half. Use the knife to scrape out the seeds. Put the seeds into the whisking bowl of an electric mixer and add the empty pods to the milk.
2. Pour the milk and vanilla pods into a casserole of at least 1.5 litre/2¾ pints capacity. Add the milk powder, a couple of teaspoons of the sugar and the coffee beans. Place the casserole on a medium heat and bring the milk to the boil. As soon as it boils, turn the heat down and allow the milk to simmer for 5 minutes. Remove from the heat and leave to infuse for 20 minutes.
3. Meanwhile, add the egg yolks to the vanilla seeds in the whisking bowl, along with the remaining sugar. Turn the machine to full speed and beat until the mixture whitens and increases in volume - about 10 minutes.
4. Place the casserole back on a medium heat and return the liquid to a simmer. Turn the heat down to low, then immediately pour this liquid very gently, pods and all, on to the egg mixture while still beating. Return this mixture to the casserole and place on a low heat. Stir continuously, preferably with a flat-bottomed wooden spoon. Do not boil. The custard is ready when a line drawn along the back of the wooden spoon retains its shape.
5. Have ready a bowl large enough to fit the mixture in and sit it in a larger bowl containing ice and a little cold water. When the custard is ready, pour it into the bowl and continue stirring for a few minutes until it is cold. Strain through a fine-meshed sieve. At this point the custard can be stored in a sealed container in the fridge for up to 2 days. Make sure that it is thoroughly mixed so that the vanilla seeds that have fallen to the bottom are evenly distributed.
6. Churn the custard in your ice cream machine and place in the freezer, with some clingfilm pressed on to the surface of the ice cream. Leave in the freezer for 2 hours before serving.